As a recording/reproduction apparatus for content information, a possible type includes two recording media. For example, one is a hard disk, and the other is an optical disk.
The hard disk is larger in capacity than the optical disk (e.g., 80 GB to 160 GB), and thus has such characteristics as enabling recording or reproduction of content information without preparation or forethought about how much capacity is left available. Moreover, there is no need for disk attachment from outside, thereby enhancing usability due to no cost therefor, and no more trouble for disk insertion for every recording or reproduction.
On the other hand, as to the optical disk, through recording of content information onto the optical disk, the content information can be extracted from the recording/reproduction apparatus to carry around. Also, in other recording/reproduction apparatuses, thus extracted content information can be reproduced, or other content information can be recorded onto the same optical disk. The problem here is that, for recording or reproduction of the content information as such, there needs to attach a disk to the recording/reproduction apparatus.
Another problem is that the optical disk is expensive, exemplarily with a DVD-R (Digital Versatile Disk) of 4.7 GB capacity, a write-once disk is about 1000 yen, and a rewritable disk is about 2000 to 3000 yen. Further, the capacity, per disk, available for writing is relatively small compared with a hard disk, and thus recording has to be always done with a consideration for capacity availability.
With the characteristics of hard disk and optical disk as such, the usage varies among cases, e.g., in a case of requiring recording only temporarily or requiring viewing only a few times, a hard disk may be selected for recording, and in a case of requiring permanent or semipermanent storage or requiring recording of any edition result, an optical disk may be selected for recording.
Herein, when a hard disk is selected for data recording, the frequency of a sampling clock is set to 48 kHz. On the other hand, for DVD (Digital Versatile Disk) reproduction, the frequency of a sampling clock is set to 48 kHz or 96 kHz, and with a CD (Compact Disk) or a video CD, 44.1 kHz is used.
Conventionally, such a sampling clock has been generated by changing the frequency of a single master clock itself.
As a result, in an exemplary case where a hard disk is recorded with data using a clock of 48 kHz frequency while a CD is reproduced using a clock of 44.1 kHz frequency, the need arises to change the frequency setting made to the master clock every time mode switching is made from recording to reproduction. Therefore, this causes a problem of taking time to derive clock stabilization, and as a result, output audio is interrupted at every switching, momentarily failing in smooth audio switching.
The present invention is proposed in consideration of such circumstances, and an object thereof is to provide instantaneous content switching.